Frontal Attachment Device for Syringe with Rotationally Activated Retractable Needle

ABSTRACT

A medical device attachable to the front of a conventional syringe and having a hub assembly selectively attachable to the syringe, a nose projecting forwardly from the hub assembly, a rearwardly biased needle retraction mechanism seated inside the nose, a retractable needle projecting forwardly of the nose, and a fluid flow path from the fluid chamber through the hub assembly, nose, needle retraction assembly and needle, wherein the needle is retracted into the nose and a retraction tube external to the syringe by rotating the syringe relative to the nose.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(e) of theearlier filing date of U.S. Provisional Patent Application No.61/737,263 filed Dec. 14, 2012.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to the use of conventional syringes incombination with a newly disclosed frontal attachment having aretractable needle. The invention relates more particularly to a medicaldevice comprising in combination a needle, nose and hub assemblyattachable to a conventional syringe preferably having a forwardlyfacing luer lock connector. The subject device has a needle retractionmechanism that is activated by rotating the syringe barrel relative tothe nose of the device to retract the needle from a patient and propelit into the nose and a retraction tube that is part of the hub assembly.

2. Description of Related Art

Conventional syringes comprising a generally cylindrical barrel, a fixedneedle projecting forwardly from the barrel, and a plunger slidablydisposed inside the barrel through an opening in the rear of the barrelare well known. More recently, syringes have been made with a luerconnector on the front of the barrel to which a needle hub is attachableto allow needles of different gauges or sizes to be used with a commonlyconfigured barrel.

Even more recently, in an effort to control the spread of blood-bornepathogens and the incidence of contamination by contact with eitherexposed needles or bodily fluids, syringes having fixed or changeableneedles have been designed to embody various “safety” elements. Such“safety” elements should desirably include a retractable needle, butmany products marketed as having “safety” elements include, for example,covers or guards that are manually operated by medical personneladministering an injection to shield or cover the needle tip followingremoval of the needle from a patient.

Some previously disclosed needle retraction systems without changeableneedles are activated either manually or automatically by application ofa force upon completion of an injection to force the needle and needletip back inside a retraction chamber. The only known syringe having achangeable, retractable needle does not have a conventional luer lockconnection, and the retraction mechanism is activated by the applicationof a forwardly directed force to the plunger handle following removal ofthe needle from a patient, thereby exposing the needle and also exposingthe user to the risk of needle-stick injury.

U.S. Pub. No. 2006/0155244 to Popov discloses a venipuncture device thatrotates a port unit following needle retraction. The retraction chamberis disposed inside the medical device, is not part of the frontalattachment and remains stable while the port unit is moved rotationallyrelative to the retraction chamber following needle retraction. Thefrontal attachment disclosed there cannot be used with a generic luerlock syringe.

Although many advancements in syringe technology have been made inrecent years, a frontal attachment device is needed that can be usedwith a standard syringe having a conventional luer lock connector, thatoffers the advantages of a changeable needle in combination with theadvantages of a retractable needle providing sufficient retraction forceto retract the needle while inserted into a patient, and that can beactivated by the application of a rotational force to the syringe barrelwhile stabilizing the nose without applying a forwardly directed forceto the plunger or the needle.

SUMMARY OF THE INVENTION

A medical device is disclosed that comprises a hub assembly selectivelyattachable to the front of a conventional syringe, a nose projectingforwardly from the hub assembly, a rearwardly biased needle retractionmechanism seated inside the nose, a retractable needle projectingforwardly of the nose, and a fluid flow path from the fluid chamberthrough the hub assembly, nose, needle retraction mechanism and needle,wherein the needle is retracted following use into the nose and aretraction tube external to the syringe by rotating the syringe relativeto the nose. As used throughout this disclosure, the terms “attachable,”“detachable” and “changeable” are generally used to characterize frontalattachments, such as needles or needle/hub combinations, that areselectively attachable to, detachable from, or otherwise changeable inrelation to a syringe for purposes such as, without limitation,selecting a particular gauge needle for a particular clinical use.

A medical device as disclosed here can be configured to be attachable tothe front of a conventional syringe having a luer lock connector. Ifdesired, a medical device as disclosed here can also be made with asnap-on or other attachment mechanism instead of a conventional luerlock connector provided that the syringe with which it is used iscooperatively configured. A medical device as disclosed here desirablycomprises a needle that is retractable, and retraction is activated byapplying rotational rather than axial force to the syringe barrel. Asatisfactory medical device as disclosed here desirably has sufficientretraction force to retract a needle that is still inserted into apatient's body and thereby prevents exposure of the contaminated needleto others. A medical device as disclosed here desirably utilizes aretraction tube that is not embodied in the syringe or plunger handle,and is instead part of the attachable hub assembly.

A satisfactory hub assembly for use in the invention as disclosed herecomprises a hub disposed forwardly of the plunger, a retraction tubelaterally spaced apart from the hub, and a frame member interconnectingthe hub and the retraction tube in substantially fixed, laterallyspaced-apart relation to each other. A medical device made in accordancewith the invention desirably further comprises a nose projectingforwardly from the hub and is attached to the frame so as to permit thehub assembly to move laterally in relation to the nose between a firstposition axially aligned with the hub and a second position axiallyaligned with the retraction tube. A rearwardly biased needle retractionmechanism comprising a needle holder and retraction spring is desirablyseated inside the nose; and a retractable needle projects forwardly ofthe nose. A fluid flow path is thereby provided from the fluid chamberof a syringe through the hub, nose, needle retraction assembly andneedle; and an annular fluid seal is desirably disposed around a portionof the fluid flow path between the hub and the nose.

Following an injection using a syringe provided with the medical devicedisclosed here, a clinician administering the injection desirably graspsa stabilizer tab provided at the nose of the device with the thumb andfinger or fingers of one hand to stabilize the body and nose, and withthe other hand, rotates the syringe barrel in a clockwise direction (thesame direction in which the barrel is rotated during attachment of thesyringe to the device prior to use). As the body and nose arestabilized, the syringe barrel and the attached hub assembly are rotatedrelative to the nose, which first causes the hub to slide laterally outof coaxial alignment with the head of the needle holder. As the hubslides out of engagement with the rearwardly biased needle holder,preferably in a curvilinear arc, a portion of the frame member disposedbetween and connecting the hub to the laterally spaced-apart retractiontube comes into abutting engagement with the needle holder to continueholding the retraction spring in its compressed position. The needleholder remains rearwardly biased until such time as a forwardly facingopening into the retraction tube sufficiently approaches coaxialalignment with the needle holder to allow the compressed retractionspring to propel the needle holder rearwardly into the retraction tube.As this occurs, the needle holder also carries the attached needlerearwardly to a fully retracted position where the needle is releasedfrom the patient and the needle tip no longer projects forwardly fromthe nose.

In this way, the medical device disclosed here is configured to convertrotational motion of the syringe to curvilinear translationalrealignment of the nose and the needle holder from coaxial alignmentwith the hub to coaxial alignment with the retraction tube.

BRIEF DESCRIPTION OF THE DRAWINGS

The apparatus of the invention is further described and explained inrelation to the following drawings wherein:

FIG. 1 is a side elevation view of one embodiment of a syringe havingselectively attached to its front end one embodiment of a medical devicecomprising in combination a nose, a needle or cannula projectingforwardly of the nose, a needle retraction mechanism seated inside thenose, and a hub assembly;

FIG. 2 is a cross-sectional view of the apparatus of FIG. 1 taken alongline 2-2 of FIG. 9;

FIG. 3 is an exploded perspective view of the apparatus of FIG. 1;

FIG. 4 is an enlarged detail view of the attachable medical device ofFIG. 1;

FIG. 5 is a side elevation view of the apparatus of FIG. 1 with thesyringe plunger advanced to the post-injection position and the hubassembly rotated clockwise relative to the nose;

FIG. 6 is a cross-sectional view of the apparatus of FIG. 5 taken alongline 6-6 of FIG. 10;

FIG. 7 is a side elevation view of the apparatus of FIG. 5 with theplunger advanced to the post-injection position and the hub assemblyrotated further clockwise relative to the nose;

FIG. 8 is a cross-sectional view of the apparatus of FIG. 5 taken alongline 6-6 of FIG. 10;

FIG. 9 is a front elevation view of the apparatus of FIG. 1;

FIG. 10 is a front elevation view of the apparatus of FIG. 5;

FIG. 11 is a front elevation view of the apparatus of FIG. 7;

FIG. 12 is a rear elevation view of the apparatus of FIG. 1;

FIG. 13 is a rear elevation view of the apparatus of FIG. 5;

FIG. 14 is a rear elevation view of the apparatus of FIG. 7; and

FIGS. 15-17 are right, left side and front elevation views,respectively, of the medical device of FIG. 1, with a needle coverinstalled prior to use.

Like reference numerals are used to describe like features in allFigures of the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIGS. 1 and 2 depict an assembled combination 20 of syringe barrel 24,having a luer lock connector 47, 49 disposed at the front end and aplunger handle 28 with plunger seal 44 slidably engaging the inside wallof syringe barrel 24, and a satisfactory medical device 22 of theinvention having a hub assembly 48 that is attached to luer lockconnector 47, 49 so as to establish fluid communication between fluidchamber 46 of syringe barrel 24 and needle 32. Plunger handle 28 extendsrearwardly from an opening in the back of syringe barrel 24 and ispositioned relative to syringe barrel 24 as it could be prior to theinjection of a fluid disposed inside fluid chamber 46 into a patient iftip 60 of needle 32 were inserted into the patient, recognizing that theposition of plunger seal 44 relative to barrel 24 will depend upon theamount of fluid that is drawn into fluid chamber 46. The injection forceis applied to a fluid disposed inside fluid chamber 46 through plungerhandle 28 by depressing thumb cap 30 of plunger handle 28 whilestabilizing syringe barrel 24 by applying oppositely directed fingerforce to the forwardly facing surfaces of outwardly projecting flanges26.

During or following the injection, a clinician administering theinjection can grasp the textured surfaces of outwardly projectingstabilizer tab 38 of medical device 22 to stabilize medical device 22and rotate syringe barrel 24, preferably in a clockwise direction (asviewed from the back of assembled combination 20), relative tostabilizer tab 38 of nose 35 (best seen in FIG. 4). Although medicaldevice 22 of the invention can be made so as to permit rotation ofsyringe barrel 24 in either a clockwise or counter-clockwise directionrelative to stabilizer tab 38 of nose 35 to achieve needle retraction,one or more mechanical barriers to counter-clockwise rotation of syringebarrel 24 are desirably provided to avoid accidentally unthreading luerlock connector 47, 49 of syringe barrel 20 from nose 35.

Satisfactory structural elements for use in combination 20 and inmedical device 22 of the invention are further described and explainedin relation to FIGS. 1-4. Medical device 22 as shown comprises nose 35,a retraction mechanism further comprising a needle holder 95 (FIG. 4)and a compressed retraction spring 50 seated inside nose 35, and hubassembly 48 comprising hub 72, frame member 74, retraction tube 42further comprising retraction cavity 86, and an annular fluid seal suchas fluid seal 56 that is desirably disposed between nose 35 and hub 72,preferably inside a recess 76 in the forwardly facing portion of hub 72.A plurality of radially projecting locking wedges 70, diametricallyopposed as shown, or other similarly effective engagement elements areprovided at the rear of hub 72 to facilitate locking engagement withlocking leer connector 47, 49 of syringe barrel 24.

Referring to FIG. 4, needle holder 95 as shown comprises elongatedcylindrical shaft portion 34, a larger diameter head 65, which is seatedagainst an annular shoulder inside substantially cylindrical body 36 ofnose when the retraction mechanism is seated inside nose 35 prior toattaching nose 35 to hub assembly 48 as further described below. Priorto seating needle holder 95 inside body 36 of nose 35, retraction spring50 is desirably compressed (spring 50 is shown compressed in FIGS. 2-4and relaxed in FIG. 8) between an annular nose 39 near the front of body36 (best seen in FIG. 8) and annular shoulder 64 (FIG. 4) on theforwardly facing surface of head 65 of needle holder 95. The length ofcylindrical shaft portion 34 of needle holder 95 is desirably such thatthe forwardly extending end of shaft portion 34 will project slightlybeyond the front of body 36 as seen in FIG. 1.

As shown, nose 35 further comprises substantially cylindrical body 36having a rearwardly facing collar 92, and an outwardly projectingstabilizer tab 38 with textured gripping elements 40. Body 36 of nose 35desirably further comprises an attachment tab 100 (FIG. 6) projectingradially outward below the longitudinal axis through interior cavity 62that has a rearwardly projecting, split cylindrical boss 58 configuredto snap into a cooperatively aligned orifice 68 in frame member 74 ofhub assembly 48. Nose 35 is thereby rotatably attached to hub assembly48 with the axis of rotation offset being offset from the longitudinalaxes through hub 72 and retraction tube 42 so as to define an arcthrough which hub assembly 48 can be moved translationally from a firstposition characterized by coaxial alignment of hub 72 with body. 36 to asecond position characterized by coaxial alignment of retraction tube 42with body 36 to initiate retraction following injection. Although thestructural elements as disclosed are satisfactory for rotatably mountingnose 35 in relation to hub assembly 48, it will be appreciated by thoseof ordinary skill in the art upon reading this disclosure that otherstructural elements and configurations can be substituted for thoseparticularly disclosed here to achieve the same functionality within thescope of the invention. Broadly stated, such functionality comprisesrotating a syringe barrel following injection to move the barreltranslationally relative to a nose portion comprising a retractionmechanism to initiate retraction of a needle from a patient into acavity inside a retraction tube so that the tip of the needle no longerprojects forwardly of the barrel.

As shown in FIG. 3, a syringe suitable for use with medical device 22 ofthe invention can comprise barrel 24 with radially projecting flanges 26disposed along the rear portion of barrel 24, an engagement structuresuch as luer lock connector 47, 49 attachable to hub assembly 48,plunger seal 44 attached to mounting boss 88 of plunger handle 28, and athumb cap 30 to facilitate the application of a forwardly directed forceto plunger handle 28 relative to barrel 24 during injection. As shown,tapered luer member 49 comprising a substantially cylindrical bore 51cooperates with annular collar 47 having internal threads 51 disposed inspaced-apart relation to tapered luer member 49 to form luer lockconnector 47, 49 that is engageable with locking wedges 70 of hub 72 toprovide a fluid-tight seal between hub 72 and syringe barrel 24. Whencombination 20 is assembled as shown in FIG. 1, a continuous fluid flowpath is formed from fluid chamber 46 (FIG. 2) through interior 84 of hub72, interior 66 of fluid seal 56, interior 94 of needle holder 95, andneedle 32 (FIG. 4).

Referring to FIGS. 5 and 6, the assembled combination 20 is again shown,but this time with plunger handle 28 advanced relative to syringe barrel24 to the point it will be following an injection, when plunger seal 44has forced the fluid out of fluid chamber 46 as previously shown anddescribed in relation to FIGS. 1 and 2. This is the position in whichplunger handle 28 will desirably remain relative to syringe barrel 24during activation of the retraction mechanism and retraction of needle32. By comparing the position of retraction tube 42 in FIG. 5 to thatshown in FIG. 1, it is apparent that rotation of barrel 24 andretraction tube 42 relative to stabilization tab 38 of nose 35 hasalready been initiated.

Referring to FIGS. 7 and 8, the assembled combination 20 is again shown,and by comparing the position of retraction tube 42 in FIG. 7 to thatshown in FIG. 5, it is apparent that rotation of barrel 24 andretraction tube 42 relative to stabilization tab 38 of nose 35 hascontinued to a point where retraction has occurred, and retractionspring 50 has propelled needle holder 95 in retraction tube 42 to aposition where no portion of needle 32 is exposed forwardly of body 36.

FIG. 9 depicts the relative positions of the components of combination20 as in FIG. 1, but viewed from the front. FIG. 12 depicts the relativepositions of the components of combination 20 as in FIG. 1, but viewedfrom the rear.

FIG. 10 depicts the relative positions of the components of combination20 as in FIG. 5, but viewed from the front, with arrow 102 showing thedirection of rotation of frame member 74 of hub assembly 48 relative tostabilization tab 38. FIG. 13 depicts the relative positions of thecomponents of combination 20 as in FIG. 5, but viewed from the rear,with arrow 106 showing the direction of rotation of retraction tube 42and syringe flanges 26 relative to stabilization tab 38.

FIG. 11 depicts the relative positions of the components of combination20 as in FIG. 5, but viewed from the front, with arrow 104 showing thedirection of rotation of frame member 74 of hub assembly 48 relative tostabilization tab 38. FIG. 14 depicts the relative positions of thecomponents of combination 20 as in FIG. 5, but viewed from the rear,with arrow 108 showing the direction of rotation of retraction tube 42and syringe flanges 26 relative to stabilization tab 38.

Nose 35, needle holder 95, hub assembly 48, syringe barrel 24 andplunger handle 28 are all desirably moldable from a suitable moldablepolymeric material. Such materials and molding methods are believed tobe well known to those of ordinary skill in the art. Similarly, it willbe appreciated by those of skill in the art of syringe design andmanufacture that a medical device such as medical device 22 disclosedhere can be used with syringes that are either pre-filled or not, andthat may comprise component portions made of glass or other suitablematerials for particular applications. Similarly, it will be appreciatedthat fluid seal 56 and plunger seal 44 are desirably made of a rubberyor elastomeric polymeric material of the types commonly known for use insuch medical applications. Similarly, it will be appreciated thatmaterials used in the fabrication of this and other medical devices mustbe approved by the relevant regulatory authorities for use in suchdevices. Retraction spring 50 and needle 32 as disclosed are desirablymade of stainless steel or any other similarly effective material. Aneedle cover 37 for medical device 22 is shown in FIGS. 15-17 for usewith needle 32 while it is disposed in the forwardly projecting positionprior to use, and it will be appreciated by those of skill in the artthat such needle covers 37 are needed to protect needle 32 fromcontamination or damage during shipment and storage, and can be designedand fabricated using known technology.

Other alterations and modifications of the invention will likewisebecome apparent to those of ordinary skill in the art upon reading thisspecification in view of the accompanying drawings, and it is intendedthat the scope of the invention disclosed herein be limited only by thebroadest interpretation of the appended claims to which the inventorsare legally entitled.

We claim:
 1. A medical device selectively attachable to a syringe havinga barrel with a front end and a back end, a plunger slidably disposedinside the barrel, a fluid chamber disposed forwardly of the plunger,and a plunger handle projecting rearwardly from an opening in the backend of the barrel, the medical device comprising: a hub assemblycomprising a hub disposed forwardly of the plunger, a retraction tubelaterally spaced apart from the hub, and a frame member interconnectingthe hub and the retraction tube in substantially fixed, laterallyspaced-apart relation to each other; a nose projecting forwardly fromthe hub; a rearwardly biased needle retraction mechanism seated insidethe nose; a retractable needle projecting forwardly of the nose; a fluidflow path from the fluid chamber through the hub, nose, needleretraction assembly and needle; wherein the barrel and hub assembly aremanually rotatable by a user through an arc relative to the nose from afirst position wherein hub and barrel are coaxially aligned with theneedle and the needle retraction mechanism to a second position whereinthe retraction tube is coaxially aligned with the needle and needleretraction mechanism to allow the retraction mechanism to force theneedle rearwardly into the retraction tube so that the needle no longerprojects forwardly of the nose.
 2. The medical device of claim 1 whereinthe hub comprises a rearwardly facing first attachment element that isselectively engageable with a cooperating second attachment elementdisposed at the front of the barrel.
 3. The medical device of claim 2wherein the first and second attachment elements comprise a luer lockconnector.
 4. The medical device of claim 3 wherein the first attachmentelement comprises a plurality of spaced-apart, radially projecting lugs.5. The medical device of claim 2 wherein the second attachment elementcomprises at least one female thread disposed inside a collar projectingforwardly from the barrel.
 6. The medical device of claim 1 wherein thenose is connected in rotatable relation to the frame.
 7. The medicaldevice of claim 1 wherein a fluid seal is disposed between the nose andthe hub.
 8. The medical device of claim 7 wherein the fluid seal isseated inside an annular recess in a front face of the hub.
 9. Themedical device of claim 7 wherein the fluid seal is an elastomeric ring.10. The medical device of claim 1 wherein the needle retractionmechanism comprises a needle holder and a spring.
 11. The medical deviceof claim 10 wherein the needle holder is biased against a fluid sealdisposed between the nose and the hub whenever the barrel and hubassembly are disposed in the first position.
 12. The medical device ofclaim 10 wherein the needle holder is biased against the frame wheneverthe barrel and hub assembly are disposed between the first position andthe second position.
 13. The medical device of claim 10 wherein theneedle holder is aligned with an opening in the front of the retractiontube whenever the barrel and hub assembly are disposed in the secondposition.
 14. The medical device of claim 10 wherein a portion of theneedle holder projects forwardly from the nose.
 15. The medical deviceof claim 10 wherein the spring is compressed between an annular surfacein the front of the nose and an annular shoulder on the needle holderwhenever the barrel and hub assembly are disposed in the first position.16. The medical device of claim 1 wherein the nose further comprises aradially projecting stabilizer tab that is grasped by a user to hold thenose in a substantially fixed position relative to a patient whilerotating the barrel and hub assembly from the first position to thesecond position.
 17. The medical device of claim 16 wherein the radiallyprojecting stabilizer tab is textured to render it more graspable by auser.
 18. The medical device of claim 1 wherein the frame comprises anorifice disposed proximally to the hub and to the retraction tube, andwherein the nose comprises a rearwardly extending boss that is insertedthrough the orifice and snaps into rotatable engagement with the frame.19. The medical device of claim 16 wherein the nose and the hub assemblyare cooperatively configured to allow rotation of the barrel and hubassembly in a clockwise direction relative to the nose as viewed fromthe back end of the barrel when the stabilizer tab is grasped by theuser while rotating the barrel and hub assembly from the first positionto the second position.
 20. The medical device of claim 16 wherein thenose and the hub assembly are cooperatively configured to restrictrotation of the barrel and hub assembly in a counter-clockwise directionrelative to the nose as viewed from the back end of the barrel when thestabilizer tab is grasped by the user while rotating the barrel and hubassembly from the first position to the second position.
 21. The medicaldevice of claim 1 wherein the nose and hub assembly are each made ofmoldable polymeric material.
 22. The medical device of claim 1configured for use with a syringe having a glass barrel.
 23. The medicaldevice of claim 1 configured for use with a syringe having a plasticbarrel.
 24. The medical device of claim 1 configured for use with aprefilled syringe.
 25. The medical device of claim 1 wherein the hub,retraction tube and frame member are integrally molded from a polymericmaterial.
 26. The medical device of claim 1 wherein needle retractionmechanism provides a retraction force upon activation that is sufficientto retract the needle directly from a patient into which the needle isinserted during an injection.
 27. The medical device of claim 1 incombination with a syringe attached to the hub assembly.
 28. A medicaldevice comprising in combination: a hub assembly selectively attachableto the front of a syringe barrel having a fluid chamber disposed insidethe barrel and a plunger slidably engaging an inside wall of the barrel;a nose attached to the hub assembly so that the hub assembly isrotatable in at least one direction through a defined arc relative tothe nose; a needle retraction mechanism seated inside the nose; and aneedle projecting forwardly of the nose; wherein the needle isselectively retractable into the nose and hub assembly by rotating thesyringe and hub assembly relative to the nose.
 29. The medical device ofclaim 28 wherein the hub assembly comprises a hub providing fluidcommunication between the fluid chamber and the nose.
 30. The medicaldevice of claim 29 comprising a fluid seal disposed between the hub andthe nose.
 31. The medical device of claim 29 wherein the hub assemblycomprises a retraction tube laterally spaced-apart from the hub.
 31. Themedical device of claim 31 wherein the hub assembly comprises a framemember that connects the hub and the retraction tube in substantiallyfixed relation to each other.
 33. The medical device of claim 28 whereinthe hub assembly is rotatable in only in one direction relative to thenose immediately following an injection.
 34. The medical device of claim28 wherein the needle retraction mechanism provides a retraction forceupon activation that is sufficient to retract the needle directly from apatient into which the needle is inserted during an injection.
 35. Themedical device of claim 28 in combination with a syringe attached to thehub assembly.
 36. The medical device of claim 29 further comprising afluid flow path extending from the fluid chamber to the needle.